Direct Comparison of Gradient Modulation Transfer Functions and Acoustic Noise Spectra of the same MRI at High- (3T) and Lower-Field  (0.75T)

In this work, gradient fidelity is compared between high-field (3T) and lower-field (0.75T) configurations on the same MRI system by measuring the Gradient Modulation Transfer Function (GMTF) and audio noise spectra. Results demonstrate that at lower field mechanical resonances are reduced, leading to improved gradient fidelity and reduction of audio noise levels of up to 70%. Furthermore, it is shown that spectral peaks in the audio spectrum can be related to resonances in the GMTF, which suggests mechanical resonances can be identified using the audio spectrum.